This invention relates, in general, to semiconductors, and more particularly, to passivating semiconductor substrates.
Diodes used in high power or high voltage applications are often manufactured with an open junction. The diode is fabricated in a semiconductor substrate where the p-n junction of the diode is open or is exposed along a surface of the semiconductor substrate. Accordingly, the diode is known in the art as an open junction diode.
Individual open junction diodes are singulated from a semiconductor wafer by a conventional sawing or mechanical dicing technique. Afterwards, the open junction diodes are subjected to a wet caustic chemical etch to remove the structural damage created by the mechanical singulation process. Then, the open junction diodes are assembled and packaged. However, the open junction diodes are often damaged by physical handling or contaminated by particulates or humidity after the caustic chemical etch and before the packaging process because the junctions of the diodes are open or exposed to ambient environment that may contain contaminants.
Accordingly, a need exists for a method of passivating an open junction diode or any semiconductor substrate. The method should be cost-effective, simple, and compatible with existing semiconductor process flows.